back-up battery for cpap

Is the CPAP run on 12V or 110V?

If it is 12 volt then you could get a marine battery. Gel cell so it will not leak if tipped. The kind used for electric trolling motors. You could run it for several nights on a single charge I bet. But then you will also need some sort of recharging plan.

They can be pricey compared to a regular car battery. But not several hundred dollars.

 

Mine wouldn't run with the 12v plug without idling the engine. With the engine off after a couple of hours it would shut down and give a low voltage error. No problems like that with the inverter. Mine just may be overly sensitive to 12v voltage fluctuation.

 

I can only get good voltage out of 1 of about 6 12V sockets in my 09 cascadia.

Mikeeee

 

I use a 400 watt cobra inverter to run my APAP and use a heated humidifier as well. I also put a snuggle hose cover on it which helps to insulate the hose and retain heat from the humidifier. I have a Carrier APU on my truck but it has to be running to use the AC outlets so I am going to add an inverter and direct wire to the batteries so when the truck goes into load shed mode, the inverter will continue to operate such as the Thermal King system does.